Major functions required of a digital seismic data acquisition system include signal conditioning of analog sensor outputs, digital conversion of analog signals, external time reference, event detection, pre-event memory, data storage, operator interface, data archival and retrieval and system calibration. Such a system finds utilization for recording and analyzing all types of seismic data in the fields of seismology, geophysics, and engineering.
Previous system designs are generally more difficult to operate, have a factor sixteen less resolution, have a less than desirable digitization rate and data capacity, and/or generally not completely portable. A desirable general earthquake observation system for use in a wide variety of passive and active seismic experiments requires portability and the requisite low power requirements, a wide dynamic range, a high data resolution, a broad frequency band width, a large data storage capacity, an accurate and adjustable time standard, selectable signals from sensors, and an interactive capability permitting easy operator control and input. Unfortunately, no system is known to exist which provides all of these desirable features.